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07 M5 Black Sapphire SMG7
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Discussion Starter · #1 ·
While doing an oil change, I removed the brake booster and master cylinder in attempt to find a leaking brake line. After getting it put back together, I started it and it immediately went into limp mode with a 2000 rpm limit. I can barely get the car to move. I ran ISTA diagnostics (limited, as I am also having issues getting ISTA to work correctly) but I did see that bank 1 idle actuator was stuck at 30% while bank 2 was behaving normally. Replaced both idle actuators. No change. Intensely inspected every millimeter of vacuum line I could visually, no obvious leaks. The line in the attached picture has no vacuum but I have not traced it to see if it should. The only thing I can think is that one of the throttle actuators has failed. After spending a couple dozen hours trying to diagnose this issue, its noteworthy that on 2 seperate attempts the car did not go into limp mode and I was able to rev over 2000 rpm. But the next time I started it, limp mode returned. I guess I will try the gear replacement on both actuators and see if that does anything. I appreciate any feedback...
 

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First the tube in red circle is the fuel tank vent NOT the brake vacuum tube, the brake vacuum tube is the tube above it in the picture and it is routed to bank 2 cylinder head and I think possibly connected internally with a passage to idle actuator bank 2, this rule out bank 1 idle actuator issue. To confirm what I am saying follow the tubes.

You mentioned in other thread you having a misfire above 6K rpm, which cylinder has misfired?. Normally misfire is caused by bad spark plug, coil ,or injector, in odd cases the valve spring is broken if it always the same cylinder misfires and the compression test passed on that cylinder.

Also mentioned that when you warm up the car with misfire then restart it to get rid of the misfire, which cylinders misfire?.

What fault codes associated with EACH issue. Post the faults reports by accessing the DME fault page.

Is your brake works fine now?. Do you have DME faults for brake booster vacuum fault?.

INPA has a test for testing idle actuator but doesn't have a troubleshooting procedure to follow like ISTA, for this issue since you replaced the idle actuator you need ISTA to insert the fault in test plan and go through the process. You may manually trace the wiring to the DME for continuity, the fault code details may give us a hint.

Post the fault codes currently triggered then delete all fault and start fresh and post the fault that triggered again for each issue. Start from cold engine in the morning to catch the brake vacuum operation.
 

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07 M5 Black Sapphire SMG7
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Discussion Starter · #3 ·
I will post codes and other info ASAP. After work today, I am going to replace both throttle actuator gear sets to see if that helps. Hopefully the cold start/high rpm misfire goes away with it but I dont know if it will. I recently replaced the plugs and several coils so that makes me think it might be an injector. Like you said though, I will have to see which cylinder is misfiring fist.
 

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Discussion Starter · #5 ·
Once the actuators start to go bad changing gears will do nothing. You really have to replace them with factory actuators.
You are totally correct, however, the only actuator codes I got were due to an IA and a TA failing pre-tests.I replaced the gears and there are no more codes. All actuators are functioning properly as far as I can see. The problem now is some sort of vacuum leak at the back of the engine as you can see in my other recent posts.
 

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Discussion Starter · #6 ·
Alright well, its fixed. Just over $1000 later and many "new" parts (some were bought used on ebay) it seems to be running decently. So far, I have put about 220-250 miles on it and aside from not wanting to idle correctly occasionally on startup, which is solved by giving it a small rev or else it nearly stalls out. I am still getting a bank 2 pre-cat o2 code, but that was there before this 6-week, 2 dozen hour endeavor. It turned out to be a faulty brake booster of all things. It is interesting to note, I did the "suck test" when I originally suspected a vacuum leak, though in hindsight I guess I should have made my ex-wife do it...if you catch my meaning ;)
In total, this is everything I have replaced, this time:
1 Throttle actuator
1 set of gears for other TA
Both idle actuators
Brake booster
Master cylinder
Vacuum pump
Lots of vacuum lines and fittings
I say this to hopefully save others some time and immense frustration, if they happen to run into the same type of issue. In the beginning, I was getting somewhat contradicting error codes. What threw me off was the IA and TA codes I got along with brake/vacuum booster codes. I was having issues getting ISTA and INPA to work on both my laptops, so I was relegated to using my BG protool which meant I was unable to run many tests. Interestingly, even after clearing all codes and adaptations, I was still not able to manually activate bank 2 TA. Bank 1 would work, but bank 2 kept failing the pre-test. Conversely, when I would unhook the actuator rod, the TA would go through the pre-test just fine. Still not sure why that happened but after replacing the brake booster, it now functions properly. I have a new o2 sensor, now I just need to find the time to replace it. I am hoping and lightweight expecting this to resolve my a/f mixture issue. Bank 1 a/f target stays relatively stable while bank 2 fluctuates and stays roughly 0.8 leaner. I will report back after and update on the drivability of my Black Beast after it re-learns everything.
Thank You all for your input. This forum is absolutely invaluable, and I appreciate all of you guys helping me keep my Monster on the road and devouring the asphalt.
 

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In the beginning, I was getting somewhat contradicting error codes. What threw me off was the IA and TA codes
No, TA/IA have different codes.
Conversely, when I would unhook the actuator rod, the TA would go through the pre-test just fine. Still not sure why that happened but after replacing the brake booster, it now functions properly.
Interesting find but will have to study this further if possible. Would make more sense if it was the IA2.
Bank 1 a/f target stays relatively stable while bank 2 fluctuates and stays roughly 0.8 leaner
Pre or post cat?.
 

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Discussion Starter · #10 ·
I tried to attach a short video, but my work PC doesn't like the video. Will try again with my laptop at home. The video doesn't really show bank 2 fluctuating, it does show bank 2 about 0.8 richer than bank 1. I am assuming this is from a faulty o2 sensor (see attached photos for list of codes) I have cleared out all the codes and since then, the only ones that come back repeatedly are 2744, 277B (I have replaced the fuel cap twice and will be swapping out the charcoal cannister today, hopefully that is the problem) and 275E. Not sure if this is all related to the o2 sensor and/or fuel cap issue or not. I will swap the o2 sensor with a new one this week if I have the time and report back. Meanwhile, if anyone can lend an ear as to what's going on, I would appreciate it, as always.
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Does the scanner gives detail if you pressed on the arrow on the right of the fault code, if so I would like to see more details for codes:
2744, 273E.
277B, 2779.
2B5A, 275E.
Those pair possibly related, seems 2 different issues, how this started. Possible the bank 1 o2 sensor heater is malfunctioned. Which o2 sensor showing "0.8 richer" pre or post cats, remember the fault is pre cat sensor.
View the MAF live data and compare it with bank 1. With o2 faults check intake first then fuel and fuel pressure then ignition. without more diagnosis data or live data testing component with INPA or ISTA it is hard to understand the issue.

I will not care much at the misfire codes now unless fuel pressure is not OK. Did the engine stall?.

Replacing the charcoal filter is good for the fuel cap and the DMTL system, if the fuel tank valves are old replace them as well.
 

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Discussion Starter · #12 ·
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Does the scanner gives detail if you pressed on the arrow on the right of the fault code, if so I would like to see more details for codes:
2744, 273E.
277B, 2779.
2B5A, 275E.
Those pair possibly related, seems 2 different issues, how this started. Possible the bank 1 o2 sensor heater is malfunctioned. Which o2 sensor showing "0.8 richer" pre or post cats, remember the fault is pre cat sensor.
View the MAF live data and compare it with bank 1. With o2 faults check intake first then fuel and fuel pressure then ignition. without more diagnosis data or live data testing component with INPA or ISTA it is hard to understand the issue.

I will not care much at the misfire codes now unless fuel pressure is not OK. Did the engine stall?.

Replacing the charcoal filter is good for the fuel cap and the DMTL system, if the fuel tank valves are old replace them as well.
I attached the latest set of codes that popped up last night on a power run. Triggered limp mode at about 8100 RPM and this is the first occurrence of the fuel pressure code. Restarted after clearing codes and it did not re-occur. I just received the new fuel filter that I will be dropping in today. Changing the charcoal cannister did absolutely nothing at all. I cannot figure out why I keep getting loose fuel cap codes. I will inspect the filler nozzle soon.
As for running live data, I am still having trouble getting my laptop to communicate with the OBD system. ISTA will not recognize it so at the moment, I have no way to run diagnostics. My BG pro-tool is also down so I am screwed until I can get ISTA to work. I am also unable to upload any videos for some reason but here is what I recorded:
Cold start - smooth, proper idle
Hot Start - rough idle, almost like it has a mild cam
Car runs fine other than wanting to stall on hot start unless a quick blip to raise the revs. I am hoping that a new fuel filter and o2 sensor will remedy some of my multiple issues... at least I hop and pray it will. Will update accordingly
 

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Better to run INPA or ISTA or you throw parts blindly.
INPA is easier to install if you installed BMW standard tool from bimmergeek to at least see the fault details and live data. INPA also capable of running engine component diagnostics, DTML system, o2 sensor and heater circuit.
2788 is fuel pressure could be the filter but could also be the pump, best to replace altogether.
Fuel tank leak system has many parts involved, vent valves under the each plenum is next to replace. Leave the o2 sensor last.
I asked if pressing the arrow infront of the fault codes take you to the fault details?.
 

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Discussion Starter · #14 ·
Better to run INPA or ISTA or you throw parts blindly.
INPA is easier to install if you installed BMW standard tool from bimmergeek to at least see the fault details and live data. INPA also capable of running engine component diagnostics, DTML system, o2 sensor and heater circuit.
2788 is fuel pressure could be the filter but could also be the pump, best to replace altogether.
Fuel tank leak system has many parts involved, vent valves under the each plenum is next to replace. Leave the o2 sensor last.
I asked if pressing the arrow infront of the fault codes take you to the fault details?.
Well I just got ISTA up to operational status. Although, I might not be so lucky next time when I actually sit down and start trying to run diagnostics. It works when it wants to, that's all there is to it. ISTA can perform a fuel system leakdown test right? How do I access all this stuff? Honestly, I got a new laptop and downloaded/installed ISTA 2 months ago and have only been able to use it once...
And yes, I can see fault details... or I could until I broke my BG dongle trying to remove it. Already ordered a Thor.
 

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all the test is under Troubleshooting>Function structure, you just navigate based on system. Calibration and service functions is under that tap.
You can trigger some component and see live data by visiting the control units tree and highlight it and press "call up ECU".
 

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Discussion Starter · #17 ·
all the test is under Troubleshooting>Function structure, you just navigate based on system. Calibration and service functions is under that tap.
You can trigger some component and see live data by visiting the control units tree and highlight it and press "call up ECU".
Thanks platii. You're helpful, as always. I will run some diagnostics tomorrow.

A lot of codes, so how is your battery and alternator? This is the first thing to check.
Battery has roughly 10k miles on it, bought it new at the beginning of winter. Took it to Autozone and let it charge over the weekend since it kept dying on me due to not having sufficient time to fully charge on its own. They tested it and it passed and I am not having any problems with it now. Alternator has some miles on it but it is still working well as I average between 12.8v and 13.2v with a few systems drawing current. And actually, since I replaced the brake booster and got it sorted and running "properly" I don't have as many codes. The main "sticky" codes are both of the bank 1 o2 codes and the lambda limit. Hoping a new sensor and fuel filter will have that sorted.

On WOT, the car reeks of unburnt fuel. It is most definitely running quite rich. I should have time to replace the o2 sensor after work today, and if it's not too much of a hassle, I will go ahead and replace the fuel filter as well. And now that I am thinking about it, bank 1 is the driver side for North American models...right?
 

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Discussion Starter · #19 ·
Are you running a tune?
I have not done it myself, but I think the previous owner had a tune installed on it based on the fact that I dont have a limited top speed. I believe the North American models are limited to 155mph but I am not 100% certain on that. On yet another dreadful note, I got the dreaded red cog issue yesterday and barely made it home. Codes are: 004FA0 clutch deviation, 00510D PLCD sensor clutch position, and 00510E clutch position, redundant. I have to assume my clutch is going since the car has 125k on it and to my knowledge it has the original clutch. I tried relearning the clutch and adaptations but it did not do a damn thing. I have no idea why this car hates me so much, but I know it does. Each time I manage to get it back on the road, I get roughly a week of drivability before something else breaks or goes wrong. I take good care of it though and I love it when I can actually drive it. I did change the transmission fluid a few months ago so first chance I get, Im going to get under the car and make sure there is enough fluid in it. If anyone thinks I should try replacing the PLCD sensor before buying a clutch kit, please let me kow. I dont think the sensor is the issue but I would rather spend $500 versus $1500. Thanks everyone, and keep me in your prayers lol
 

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Based on the car mileage it is in the repair/maintenance zone. Everything wears over time and it is the time for repair, you can't go around SMG time.
Both PLCD sensor faults is PLCD. If everything old inside like old leaking slave worn out clutch and linkage, I wouldn't even trust our understanding. The PLCD can be changed without fully dropping the transmission, you can try your luck if it gives you more time, or drop the transmission and get it over with so you can enjoy it with no worries.
 
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